原文文档：http://airflow.apache.org/docs/apache-airflow/stable/_api/airflow/operators/bash/index.html 在 AirFlow 1.10 版本中，该模块为 airflow.operator.bash_operator

from airflow.operators.bash import BashOperator

If BaseOperator.do_xcom_push is True, the last line written to stdout will also be pushed to an XCom when the bash command completes

1. Parameters

• bash_command (str) – The command, set of commands or reference to a bash script (must be .sh) to be executed. (templated)
• env (dict) ：If env is not None, it must be a dict that defines the environment variables for the new process; these are used instead of inheriting the current process environment, which is the default behavior. (templated)
• output_encoding (str) – Output encoding of bash command
• skip_exit_code (int) – If task exits with this exit code, leave the task in skipped state (default: 99). If set to None, any non-zero exit code will be treated as a failure.

Airflow will evaluate the exit code of the bash command. In general, a non-zero exit code will result in task failure and zero will result in task success. Exit code 99 (or another set in skip_exit_code) will throw an airflow.exceptions.AirflowSkipException, which will leave the task in skipped state. You can have all non-zero exit codes be treated as a failure by setting skip_exit_code=None.

🔖Note: Airflow will not recognize a non-zero exit code unless the whole shell exit with a non-zero exit code. This can be an issue if the non-zero exit arises from a sub-command. The easiest way of addressing this is to prefix the command with set -e;

Example: bash_command = "set -e; python3 script.py '{{ next_execution_date }}'"

:::info 🔖Note:
Add a space after the script name when directly calling a .sh script with the bash_command argument – for example bash_command="my_script.sh". This is because Airflow tries to apply load this file and process it as a Jinja template to it ends with .sh, which will likely not be what most users want. :::

:::warning Care should be taken with “user” input or when using Jinja templates in the bash_command, as this bash operator does not perform any escaping or sanitization of the command.

This applies mostly to using “dag_run” conf, as that can be submitted via users in the Web UI. Most of the default template variables are not at risk. :::

For example, do not do this:

bash_task = BashOperator(
    task_id="bash_task",
    bash_command='echo "Here is the message: \'{{ dag_run.conf["message"] if dag_run else "" }}\'"',
)

Instead, you should pass this via the env kwarg and use double-quotes inside the bash_command, as below:

bash_task = BashOperator(
    task_id="bash_task",
    bash_command='echo "here is the message: \'$message\'"',
    env={'message': '{{ dag_run.conf["message"] if dag_run else "" }}'},
)

2. Class parameters

3. Functions